Method for embossing a coated sheet with a diffraction or holographic pattern

ABSTRACT

A method for decoration of paper or plastic sheeting and other substrates, involving a novel technique for coating and embossing the substrate. The paper or plastic sheeting is supplied with a coating of thermosensitive material, as by extrusion. The coated sheet is heated to adequately soften the coating, such as by use of a heated cylinder, and remote heat sources such as infrared heaters. The softened sheet surface is then decorated using an embossing member, to provide a diffraction pattern or hologram. Use of an embossment pattern of lesser depth than the surface roughness of the sheet before embossing provides attractive decorative patterns.

This is a continuation of copending application Ser. No. 502,537, filedMar. 30, 1990; which is a division of U.S. application Ser. No. 253,163,which is filed on Oct. 3, 1988 and is now U.S. Pat. No. 4,913,858; whichis a continuation-in-part of Ser. No. 113,689, filed Oct. 26, 1987, acontinuation-in-part of Ser. No. 234,448, filed Aug. 19, 1988, and acontinuation-in-part of Ser. No. 064,039, filed Jun. 19, 1987, all nowabandoned.

BACKGROUND

1. Field of the Invention

This invention relates to the decoration of sheeting and moreparticularly to the decoration of materials such as standard,lightweight, cellulosic sheets. This invention also relates to theembossment of plastic film and more particularly the high speedembossment of such films with holographic patterns.

2. Description of the Prior Art

Cellulosic sheets are normally decorated by imprinting. To achievespecial effects, this requires special inks and relatively complexprinting procedures. In addition, some decorative effects cannot berealized by imprinting. Complex procedures limit the speed at whichdecoration can take place.

In addition, it is difficult to achieve shallow or surface embossmentfor cellulose sheets because of their grainy texture.

There are wide-spread applications for embossed plastic films. Oneexample is provided by plastic films embossed with holographic patterns.These are used in applications where security sensitive items such asholographic labels are used.

A present practice is to emboss the plastic film with holographicpatterns at a relatively slow rate of travel, on the order of 25-30 feetper minute. This is done by direct embossing of polyester film before orafter metallization. The film is a single-heated, and softened somewhat,in order to accept an embossing pattern. If the film is softened to thepoint where it readily accepts the pattern there can be significantdistortion of the film and consequently of the pattern embossed upon it.This has resulted in the need to emboss at relatively low temperatures,i. e., below the true softening temperature of the film, slow speeds andrelatively high pressures. Such films are typically embossed at ratesunder about 50 feet per minute.

Another procedure involves a large number of rolls disposed in seriesand preheated before embossment. It is necessary to use a large numberof preheated rolls for careful control over the temperature and theaccomplishment of embossment without distortion of the plastic film. Inorder to reach a desired compromise between web speed and temperature,the leader of the plastic film that is to be embossed is fed through acomplex series of rolls. The operation is initially started at a slowspeed which is programmed to increase to a desired speed consistent withthe temperature at which suitable embossment should take place withoutdamaging the underlying plastic film. Not only is this complex but thefinal speed that is achievable in practice is in the range from about30-50 feet per minute.

In a further procedure a film of polyvinylchloride is extruded. The filmstill retains some of its residual heat when the embossment takes place,but this is awkward. If there is too much of a delay between the time ofextrusion and the time of embossment, the pattern is relatively poor.Another objection is that an extruder must be tied to an embossingarrangement.

It is accordingly an object of the invention to provide an alternativeand simplified technique for the decoration of sheeting. A relatedobject is to achieve special effects without printing. Another relatedobject is to achieve decorative effects that cannot be realized byordinary imprinting.

It is an object of the invention to facilitate the embossment of plasticfilm, particularly films that are to have holographic or diffractionpattern images. A related object is to facilitate the production ofsecurity sensitive material such as holographic labels.

Another object is to increase the rate at which plastic films can beembossed without significant distortion. A related object is to avoidthe need for embossment at relatively low temperatures, slow speeds andrelatively high pressures.

A further object of the invention is to eliminate the need for a largenumber of preheated rolls in order to control film temperature andaccomplish the desired embossment without plastic film distortion.

Another object of the invention is to eliminate the need for embossmentfollowing extrusion, with the embossment relying upon the residual heatof extrusion in order to form a suitable pattern. A related object is toimprove the quality of patterns associated with embossment followingextrusion. Another related object is to eliminate the need for operatingembossing apparatus in conjunction with an extruder.

A further object of the invention is to realize desired decorativeeffects for cellulosic sheeting, at high speed, despite the grainytexture.

SUMMARY OF THE INVENTION

In accomplishing the foregoing and related objects the inventionprovides for embossing the coating of a substrate, such as papersheeting. The coating is a thermosensitive material such aspolyethylene, polystyrene, polyvinyl chloride and like thermoplastics orsemicured thermosets ("B" staged) which have discernible thermoplasticproperties. The term thermoplastic, as used hereinafter, shall beconstrued to include such materials.

The paper advantageously is supplied with the coating of thermoplasticmaterial. In the case of polyethylene, the coating is easily applied byextrusion. The thermoplastic coating may typically be applied in asolvent or water base by gravure or reverse roll methods.

When the coated sheet is heated, the outer layer of thermoplasticmaterial becomes softened. To assure proper softening, adequate heatingmust be employed. This can take the form of a heated cylinder andadditional heaters can be disposed away from the sheet surface. Infraredheaters can be used which operate at temperatures on the order of 1000°F. The thermoplastic coating is heated to above its softeningtemperature before the embossing. The decoration of the softened sheetsurface is accomplished with an embossing member, which can take theform of a roll, rollers, belt or platen. The embossing member transfersan embossment pattern, which can be applied to the softened coating onthe sheeting substrate. The result is a decorated sheet.

The embossment desirably has a diffraction pattern or hologram in whichthe depth is less than one micron and typically under 0.5 microns. Whenthe substrate is paper, the coating that is embossed has a surfaceroughness with a depth, before embossing, greater than about 0.7 micron.It would be expected that with a depth of surface roughness that exceedsthe depth of the diffraction pattern, a suitable transfer of thediffraction pattern to the thermoplastic surface could not be achieved,or, if achieved, would at least be distorted in the area where thesurface roughness exceeds the diffraction depth of the embossmentmember, particularly if the coating is heated to above its softeningtemperature.

In the practice of the invention it has been discovered surprisinglythat a desirable diffraction pattern is produced. The reason for thisresult is not fully understood. In the present invention the softenedcoating is theorized to flow into the low depth areas of the substrateproducing a more uniformly embossed surface. Other decorative effectscan be achieved by the invention, for example, a matte background. Insuch a case, the decorating roller can be sandblasted or otherwisetreated to produce a roughened surface, or the coating surface can bemade matte prior to the embossing step. Upon completion of the process,with a matte background and a desired image elsewhere, the result is adesired, decorative material. The invention can be used for theapplication of diffraction gratings and holographic interferencepatterns by the decorating member. In addition, the coating surface canbe metallized.

Another aspect of the invention is to use a substrate which is aheat-resistant plastic film. An aspect of the invention is that itprovides a high speed embossable plastic film formed by the heatresistant base film and a thermoplastic coating upon the base film. Thethermoplastic coating has a softening temperature below that of the heatresistant film. This provides a film which is embossable with distortionresistance at relatively high speeds. The heat resistant plastic can bepolyethylene terephthalate and the thermoplastic coating illustrativelyis polyvinylchloride. An embossing pattern in holographic form can beformed on the thermoplastic layer which desirably contains a releaseagent such as hydroxylated polysiloxane.

In accordance with another aspect of the invention, the thermoplasticcoating can be opaque or tinted to provide a lustrous embossing pattern.This gives the appearance of metallization. A side of the thermoplasticcoating opposite embossment can be metallized directly or indirectly.

In accordance with a procedure for the high speed embossment of plasticfilm, a first step is to provide a heat resistant plastic film with athermoplastic coating that has a softening temperature below theheat-distortion temperature of the heat resistant film. Thethermoplastic is then heated to above its softening temperature and thesoftened thermoplastic layer is contacted with an embossing master.

The contacting step involves the contact of the thermoplastic layer withan embossing master, which is an embossing roller, a metallic die, or ametallized plastic film, on the roller. The master can be used to form aholographic or diffractive pattern in the thermoplastic layer.

In a high-speed embossable sheeting pursuant to the invention, thethermoplastic surface is adapted for diffraction embossment with arelease agent preferably of hydroxylated polysiloxane blended within thethermoplastic. The sheeting may include an embossing pattern in thethermoplastic surface, which can be holographic. When the thermoplasticis opaque or tinted, the result is a lustrous embossing pattern. Wherethe thermoplastic is transparent, it can have a side opposite theembossing pattern which is metallized.

In a method of high-speed embossing of a thermoplastic surface coated ona paper, or heat-resistant plastic substrate, a thermoplastic surfacecontaining a polysiloxane release agent is provided. The thermoplasticsurface is heated to above its softening temperature; and the softenedthermoplastic surface is contacted with an embossing master attemperatures below the thermoplastic softening temperature. The presenceof the release agent facilitates the release of the embossing masterduring embossing.

The thermoplastic can have opposed surfaces of which the surface facingaway from a film is embossed and the surface facing toward the film ismetallized. This provides an embossed metallizable member which isproducible at relatively high speeds. The embossed thermoplastic can beimprinted with a compatible material to selectively eliminate theembossing pattern at prescribed print positions. The embossedthermoplastic surface can also be directly metallized. The process andembodiments of the invention make practicable high-speed embossing ofsheeting.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing which shows extrusion coating;

FIG. 2 is a schematic which shows heating of the coated substrate ofFIG. 1;

FIG. 3 is a perspective illustration of one form of embossment;

FIG. 4 is a perspective illustration of an alternative form ofembossment;

FIG. 5a is a cross section of the laminate showing the surface roughnessof the thermoplastic layer;

FIG. 5b is a cross section of the laminate after embossing;

FIG. 6 is a sectional view of a portion of a plastic film compositewhich is embossable at relatively high speeds in accordance with theinvention;

FIG. 7 shows the composite of FIG. 6 after having been embossed by anembossing master;

FIG. 8 illustrates embossment of the composite of FIG. 6 where theembossed thermoplastic layer contains a release material to prevent thethermoplastic from sticking to the embossing master;

FIG. 9 illustrates a composite employing an opaque coating which hasbeen embossed by a master to produce a lustrous, metallic-likeembossment, without metallization; and

FIG. 10 is a composite in accordance with the invention wheremetallization has taken place on a surface opposed to an embossedthermoplastic surface.

DETAILED DESCRIPTION

Standard paper sheeting 10 is provided with a thermoplastic coating 11,for example, from an extrusion coater 120 (FIG. 1). A typical coating isof polyethylene. The thermoplastic coating 11 may also be applied in asolvent, or water base, using gravure or reverse roll methods.

Paper sheeting 10 thickness usually varies from about 40 microns toabout 100 microns. The paper sheeting 10 can also be of cardboard stockhaving a thickness up to about 750 microns. (Note: 25.4 microns equal0.001 inch). The thermoplastic coating 11 thickness advantageously isbetween about 1.5 microns to about 50 microns and can even be higher.The preferred range for the thermoplastic coating 11 thickness has beendetermined to be about 4 to 10 microns. This corresponds to a coatingbasis weight, e.g., of polyethylene, of between about 2 to 6 lbs. per3,000 sq. ft. of coating applied.

Once the coating 11 is applied to the surface 10s of the paper substrate10, the coated substrate is applied to a heated cylinder 21 (FIG. 2).This causes the substrate to become heated and to provide thermaltransfer through the substrate to the upper outer layer of the plasticmaterial 11.

To assure proper softening, additional heating can be employed (FIG. 2).Particularly suitable is infrared heater 23 which can be disposed awayfrom the surface 11 that is being softened. Such a heater 23 is operatedat heater surface temperatures of about 1000° F. In addition, a secondheated roll 22 may be employed.

The thermoplastic (thermally deformable) coating 11 just prior toembossing should be heated to well above its softening temperature. Apractical limit to heating coating 11, however, is about 450° F. abovewhich temperature paper begins to degrade. In operation, it has beendetermined that coating 11 should be heated to temperature typicallybetween about 250° F. to 350° F., which range represents a preferredrange for most thermoplastic coatings to be embossed in the process ofthe present invention.

Once the outer layer 11 of plastic, such as polyethylene, has beensoftened, an embossing arrangement is employed for decoration (FIG. 3 orFIG. 4). In FIG. 3 the arrangement uses a heated platen 32, an embossingroll 31 and a pressure nip roll 33. The embossing roller 31 is aconventional embossing master which has the desired embossing pattern.This pattern is produced on the roller or rollers by engraving,embossing with a hard material or mounting patterned plastic films ormetal films onto the surface of the roller. When the embossing roller 31contacts the softened plastic surface 11, it transfers an embossmentpattern to the coating 11 on the paper and simultaneously cools thecoating so that it will not flow after being removed from the embossingroller. Thus, in the case of polyethylene, an embossed pattern becomesembedded in the polyethylene surface. The result is decorated,polycoated paper.

The temperature of the embossing master (embossing roller 31) must bebelow the softening temperature of thermoplastic coating 11. Thetemperature of embossing roller 31, however, should not be so low as toharden coating 11 before the embossing is completed. It has been foundthat the preferred temperature for embossing roller 31 (embossingmaster) can vary depending on its thermal conductivity and specificheat, the embossing nip pressure, operating speed and the temperature towhich coating 11 is heated immediately prior to contact with theembossing roller 31. Despite the large number of variables, applicanthas determined that the embossing master (roller 31) preferredtemperature in the process of the present invention is between about 20°F. to about 60° F. below the self-adhesive temperature of thethermoplastic coating 11. The self-adhesive temperature of thethermoplastic coating 11 is defined as the minimum temperature at whichtwo layers of the coating (excluding any release agents added to thecoating) will mutually adhere when pressed together. It has beendetermined that, in the context of the present process, this generallyplaces the preferred embossing master (embossing roller 31) temperaturebetween about 100° F. and 200° F.

In FIG. 4, a take-off roller 34 has been added to allow longer contactof the embossed surface with embossing roll 31. The longer contact timeallows better cooling of the embossed surface to facilitate easy partingof the web from the embossing roll and to prevent possible reflow of thecoating and loss of the embossed pattern. The pressure nip roller 33 maybe metal or be surfaced with a resilient material such as rubber. Theforce applied between the pressure nip roller 33 and the embossingroller 31 should range from about 50 pounds per lineal inch (PLI) toabout 1000 PLI along the length of contact between these two rollers.The force applied between pressure nip roller 33 and embossing roller 31may advantageously be 50 to 300 pounds per lineal inch but is morepreferably in a range between about 100 to 500 pounds per lineal inch.

This latter range corresponds approximately to between about 400 to2,000 pounds per square inch. (Contact pressure between two cylinders,or rollers, is often reported in pounds per lineal inch (PLI) ratherthan pounds per square inch because the exact width (i. e., area) ofcontact between two rollers is not usually known, but the force appliedand contact length are generally known.)

The surface of the embossing master (roller 31) should be hard anddistortion resistant so the embossing pattern is preserved during theembossing step. The opposing roller, i. e., nip roller 33, should befirm but also be somewhat resilient. This allows nip roller 33 to applya nearly uniformly distributed pressure to the back of the sheetingbeing embossed. It has been determined that nip roller 33 can be quitefirm, typically with a Shore A durometer hardness (ASTM D-412) readingof about 40 to about 60, or even somewhat higher, and yet not be so hardas to interfere with attainment of a uniformly distributed pressure onthe back of the sheeting being embossed. The contact (dwell) time,wherein the embossing roller 31 and nip roller 33 contact the sheetingor plastic film to achieve embossing, is generally in the range of about40 milliseconds (e.g., 60 ft./min. for a 1/2 inch wide contact area) toabout 1 millisecond (e.g., 600 ft./min. for a 1/8 inch wide contactarea).

The process of the present invention permits embossing of the sheetingherein described at high rates, typically higher than 100 ft./min. Theprocess of the present invention permits embossing of the sheetingherein described at rates typically between 100 ft./min. to 800ft./min., more typically between about 200 ft./min. to about 500ft./min.

Various effects can be achieved. If the diffraction pattern is not to becontinuous, a matte background can be provided by suitable modificationof the embossing roller. Alternatively, the embossing pattern can, inparts, be filled in with coating material, such as ink or clear lacquer,in those areas where no embossed decoration is desired.

FIG. 5a shows an enlargement of the substrate 10 which is paper sheetingwith coating 11 prior to embossing. The substrate 10 has a roughenedsurface which creates in the structure, a variable thickness rangingbetween a maximum thickness t₁, and a minimum thickness t₂. The coatinghas a uniform depth d₁. After embossing, as shown in FIG. 5b, thethickness, t₃, is nearly uniform, but the coating depth now varies fromd₂ to d₃ due to the calendaring effect. The embossing pattern depth d₄is less than the original surface roughness (t₁ -t₂).

The surface roughness of the base paper 10, that is, the averagepeak-to-valley surface height variation, will typically vary from about1.0 to about 3.0 microns for clay-coated papers suitable for coating.However, rougher paper sheets 10 may also be used. For example, sheets10 having surface peak-to-valley roughness of up to 5.0 microns, or evenhigher may also be used, particularly if the thermoplastic coating 11 isapplied at high solids content as by extrusion or hot-melt methods.

After the thermoplastic coating 11 is applied, but before embossing, thesurface roughness (t₁ -t₂) will typically be somewhat lower than thesurface roughness of the base paper 10 alone. It has been determinedthat the surface roughness (t₁ -t₂), after the base coating 11 has beenapplied, may typically be about 70 to 90 percent of the original basepaper roughness. Thus the surface roughness (t₁ -t₂), after coating 11has been applied, may typically be between about 0.7 microns to about3.0 microns and as high as about 5.0 microns After embossing, theembossing depth illustrated schematically in FIG. 5b is less than theoriginal coated-surface roughness (t₁ -t₂). The embossing pattern depthd₄ will be less than 1.0 micron and may vary typically from about 0.1micron to about 0.5 micron more usually between about 0.2 to about 0.4micron.

With reference to the drawings, FIG. 6 illustrates a composite filmwhich is embossable at speeds exceeding 400 feet per minute with goodresults. The composite film 50 of FIG. 6 is formed by a heat resistantplastic film 110 and an overlying thermoplastic coating 12 containing arelease agent. The thermoplastic coating has an outer surface or a face12f which can receive an embossment as shown in FIG. 7. When aheat-resistant plastic film 110 is used as the substrate, as in FIG. 6,instead of, or in the absence of a paper substrate, the surface of thethermoplastic coating 12 thereon may be smooth. In this case, the depthof the embossment may be greater than the depth of surface roughness ofthermoplastic coating 12.

The thermoplastic coating 12 has a softening temperature which is lessthan the softening temperature of the heat-resistant plastic film 110.All the process conditions aforementioned with respect to the embossingof thermoplastic coating 11 on paper sheeting 10 apply equally to theembossing of the composite plastic film 50 as shown in FIGS. 6 to 10.However, in the case of composite plastic film 50, the coating 12 shouldsoften at least 10° F. and, preferably 40° F. and even more below theheat distortion temperature of the support film, namely, heat-resistantplastic film 110. The composite plastic film 50 should be preheatedbefore embossing to a temperature above the softening temperature ofthermoplastic coating 12, which temperature is also below the heatdistortion temperature of the heat-resistant plastic film 110. Thus,thermoplastic composite plastic film 50 should be preheated to atemperature before embossing, which is between the softening temperatureof coating 12 and the heat distortion temperature of heat-resistantplastic film 110. All other process conditions described with respect tothe coated paper sheeting 10 as referenced in FIGS. 1-4 apply as well tothe composite plastic film 50 and variations thereof illustrated inFIGS. 6-10.

In FIG. 7 an embossing master 20 is shown after having been applied tothe thermoplastic coating 12k and separated to yield an embossed surface12e. The composite formed by the film 110 at the coating 12k can beembossed at a relatively rapid rate by the embossing master 20. Theembossing master 20 may take the form of a pattern stamped embossingroller 31 or rotary metallic die or a metallized film covering roller31..

In order to avoid any tendency for the thermoplastic coating 12 of FIG.6 to stick to the embossing master 20 of FIG. 7, the thermoplasticcoating is provided with a release agent to yield the modified coating12r illustrated in FIG. 8. The presence of the release agent allowshigher speeds to be achieved during embossment. Although other releaseadditives are possible, a preferred release additive for thethermoplastic coating is a polysiloxane preferably hydroxylatedpolysiloxane. One form of such a polysiloxane is available from the DowCorning Corporation under the designation Q4-3667. This material has thefollowing chemical formula: ##STR1##

In addition to providing release properties from an embossing master,the material permits the subsequent application of additional coatings,which may be functional or decorative, to the embossed surface withoutinterfering with the adhesion of these coatings. These coatings includevacuum deposited metal and solvent or aqueous borne coatings applied byconventional coating methods.

The release material in conjunction with the embossment procedure hereindescribed is advantageously applied to any situation where a hightemperature carrier or a temperature resistant carrier is used inconjunction with a lower temperature plastic coating. It is desirable tomaintain a suitable temperature differential between the plastic coating12 and the embossing master 20. The embossing master 20 temperatureshould be below the softening temperature of the coating so that rapidembossing takes place and reflow of the plastic is avoided afterseparation of the coating.

Other procedures are illustrated in FIGS. 9 and 10. In FIG. 9 solidopaque or tinted colors can be embossed directly to give the luster andeffect of metallization without actual metallization. This involves theuse of opaque dyes or pigments to produce a brilliant diffractionpattern without metallization. Although in FIG. 9 the embossing master20 is depressed into the coating 12q, it is also possible to cast thecoating 12q on the master 20.

Another embodiment is shown in FIG. 10 where a metallized surface 13 hasa clear overcoat structure, which is illustratively formed by theheat-resistant film 110 and the coating 12k. The coating 12k isdiffraction embossed. This gives the appearance that is substantiallysimilar to that which is achieved by embossing followed bymetallization. A variation of the embodiment shown in FIG. 10 is to havethe metallic layer 13 sandwiched between heat-resistant film 110 andthermoplastic coating 12k. A paper substrate could optionally beincluded under heat-resistant film 110, i. e., film 110 would be firstcoated onto the paper substrate. This variation also produces theappearance similar to that achieved by embossing followed bymetallization. The advantage of such embodiments is that the embossmentcan take place in line with printing. The metallization step can beperformed before the embossment, and it is not necessary to perform itafter the embossment. In addition, when the embossing pattern is in thecoating, it is possible to control the pattern at will by simplyovercoating in accordance with a desired pattern that has the same, ornearly the same, refractive index as the embossed coating because theovercoated areas then are now devoid of the embossment. This permitscontrol over the embossing pattern in a very simply way withoutrequiring a change in the basic embossment that is used with metallicfilms.

EXAMPLE 1 (Solvent Borne Coating)

A coating is made consisting of 200 parts by weight of polystyrene in asuitable solvent such as toluene. To this polystyrene solution 1 part byweight of polysiloxane is added and dispersed. This coating is appliedby conventional coating methods, such as rotogravure, to a cellulosesubstrate and dried using forced hot air until all toluene is removedfrom the coating resulting in a continuous film of polystyrene on thecellulose substrate. Desired coat weight is 2.0-4.0 lbs. of driedpolystyrene per 3,000 square feet of cellulose substrate. Embossment cantake place immediately after drying while the coating remains hot or canbe achieved by subsequent re-heating and embossment of the coating onthe cellulose substrate.

EXAMPLE 2 (Water Borne Coating)

A mixture of 200 parts by weight of a styrenated acrylic emulsion and 1part by weight of polysiloxane is made. This coating is applied to acellulose substrate by conventional coating techniques, such as rollcoating, and dried using forced hot air or other means to raise thetemperature of the liquid to remove all water until a continuous film ofthe coating on the cellulose substrate is achieved. Desired coat weightis 2.0-5.0 lbs. of dried coating per 3,000 square feet of cellulosesubstrate. Embossment can occur immediately after drying while thecoating is hot or can be achieved by subsequent re-heating andembossment of the coating.

Other aspects of the invention will be apparent to those of ordinaryskill in the art. The invention therefore is not intended to be limitedto the preferred embodiments described herein but rather is defined bythe claims and equivalents thereof.

What is claimed is:
 1. The method of high speed decoration of sheetingwhich comprises the steps of:(a) providing a paper substrate; (b)providing a coating of thermoplastic material containing a release agenton a surface of said paper substrate; (c) heating the coating to atemperature above its softening temperature; and (d) contacting theheated thermoplastic coating with an embossing member under rollingpressure contact at a speed of greater than 100 feet/minute, to embossthe coating with a diffraction or holographic decorative pattern,wherein the embossing member is at a temperature below the softeningtemperature of said coating before and during said embossing.
 2. Themethod of claim 1 wherein the roughness of the paper substrate beforeembossing exceeds the depth of the embossment.
 3. The method of claim 2wherein the roughness of said substrate exceeds one micron and the depthof said embossment is less than one micron.
 4. The method of claim 2wherein the depth of surface roughness of said coating is greater than0.7 microns, and the depth of the embossment is less than the depth ofsurface roughness of the coating before embossing.
 5. The method ofclaim 1 wherein the embossing member is selected from the groupconsisting of rollers, belts and webs.
 6. The method of claim 1 whereinthe embossing member during embossing is at a temperature below theself-adhesive temperature of the thermoplastic coating.
 7. The method ofclaim 1 wherein the embossing is accomplished by passing said sheetingbetween an embossing roller and a nip roller, and wherein the forceapplied between the embossing roller and nip roller during embossing isin the range between 100 to 500 pounds per lineal inch along the lengthof contact of said rollers.
 8. The method of claim 1 wherein thethermoplastic coating before embossing is at a temperature in the range250° F. to 350° F.
 9. The method of claim 1 wherein the embossing memberduring embossing is at a temperature in the range 100° F. to 200° F. 10.A method as in claim 1 wherein the heating of said coating beforeembossing is accomplished with at least one heater not contacting thecoating.
 11. The method of claim 1 further including the step ofmetallizing the embossed coating.
 12. The method of claim 1 wherein therelease agent comprises a polysiloxane release agent.
 13. The method ofclaim 1 further comprising the step of filling in said embossed patternat least in part with an ink or lacquer coating material.
 14. The methodof claim 1 wherein said thermoplastic coating has opposed surfaces ofwhich an outer surface is embossed and an underlying surface ismetallized; thereby to provide an embossed metallized member atrelatively high speeds.
 15. The method of claim 1 wherein thethermoplastic coating contains an opaque or tinted material.
 16. Themethod of high speed decoration or sheeting which comprises the stepsof:(a) providing a paper substrate; (b) providing a coating ofthermoplastic material on a surface of said paper substrate, saidthermoplastic material including a release agent; (c) heating thecoating to a temperature above its softening temperature; and (d)contacting the heated thermoplastic coating with an embossing member inrolling pressure contact at a speed between about 100 to 800 ft./minuteto emboss the coating with a diffraction or holographic decorativepattern, wherein the embossing member is at a temperature below thesoftening temperature of said coating before and during said embossing,and wherein the depth of surface roughness of said paper substratebefore embossing exceeds the depth of the embossment.